Hi Guys,

Been a while since ive been on here. Mainly its because ive started making videos now instead of filling out forums, As you can tell by the title of this thread.... a dreaded piston engine in an RX7... Yes I get hate for it bigtime but hear me out.

Firstly I have x2 FD's My white one is a half Bridgeport 13b with single borg S362 on adaptronic etc... Its a dream
Second car is my old RX7 I bought for £200. Its always been my rough build car. Its never ever going to be mint.. I struggle to keep it out of the ditch ha.

Right.. Down to the nitty gritty, In 2018 I was in a bit of a situation where my car needed another rebuild due to running too much water methanol and breaking down the 2t lubrication (scored housings low comp). I am not a big company, I also don't have allot of money either but I am average with fabrication and making things work. As I already had my other rotary rx7 I fancied trying something different. I spent allot of time on the internet and speaking to a few trackday (circuit) guys and allot would recommend the Honda K20 engine.

Now I live in the UK. Rotary parts are very VERY rare and expensive but I can buy a Honda K20 for $400 for the full block. I then made the decision to swap the 13b out for a Honda k20. As I started the build I didn't know if it would actually live up to my expectations so I kept costs as low as possible and you can see this in my videos.

Basic specs:
Honda K20 160kmiles uncracked block
RX7 Gearbox and original prop and powerplant frame
custom 1000bhp twinplate clutch
hondata kpro
1000cc injectors
holset hx40 turbo
502bhp

Now before I get torn to bits, I still love rotary and the RX7. People shout I should have bought an S2000 blah blah blah.. 1. Idont have that sort of money, 2 I love the shape look and handling of the RX7.. and ive kept the 50/50 weight distribution and it weighs 1097kg.

anyway here is my channel if you fancy seeing what ive created. Its a good bit of fun

https://www.youtube.com/channel/UCFD...confirmation=1

Thanks
Gav.

 

The K20 is a fantastic motor. So while I do not like piston engines in RX7s, at least it's not another V8.

The weak point of the K series was always the transmission, and in this application that's eliminated from the equation.

 

Thanks man,

Well here is something I found out. JDM RX8 5 speed gearbox.. Swap the tail housing and the bell housing and you have yourself a 1999 - 2002 FD box with the uprated syncros.
They also cost a fraction of the price.

Next year im looking at going for a maxxecu (sweedish company) This ecu can control BMW M3 DCT Gearbox,
So ill end up with a 7 speed sequential double clutch tranny next year. The rx8/rx7 boxes work but seem to die around 500bhp mark... but its mostly my shifting. Im not exactly patient

 

WOW is all I can say. I have a K20A in my DC4 Integra road race/hillclimb car and it's so fantastic even NA. What I'm genuinely interested in is what you had to do to your sub frame to make it fit. I imagine the exhaust side T bracket mount wasn't too hard to implement but I'm curious what's on the other side or what you did to hold the engine up. How's the ground clearance too? I'm against piston engine swaps, but this actually has me interested!

 

This is excellent. I'm not against a k swap if my rotary ***** the bed in a serious way. You can make 1000hp in a k series.

 

Damn, that's pretty cool. I do love me some VTEC. Please post some videos of it.

Vince

 

Hmmm....

I’m appreciative of all kinds of engineering, even tho I’m **** at it myself, lol, so congrats on the conversion, looks great and obviously it works well, nice power and revs hard to boot!!

im currently toying idea’s around for my mk2 ford cortina project, ive thought about vtec, is there a bellhousing made to fit or is it a custom item for the rx7 box??

cheers, more pics too pls

krem

 

So, The subframe is still OEM but I cut the base out to fit the sump as the k20 sump is larger, I braced it all back up after when mounting the steering rack. I raised the steering rack also to help combat the bumpsteer.
Yes I just made the downpipe tie into the FD 3" EXhaust system
The engine mounts are mustom made with some 6mm steel. I bought landrover engine mounts designed for a heavier engine and propped the engine where I wanted it tilted at the right angle and taked the plate in place.
the ground clearance is great. it sits above the stock Anti roll bar. The bonnet closing was something I had my head fixed on. also the stock strut brace fits.
Thanks for your kind words dude.


Thanks brother, You can if you wanted but 500bhp is the max I like to go on the FD body. I had my last 13b at 700bhp and it was a bit too much for the chassis on racetrack I felt. Next year I might forge it and push further,
The hondata has boost by rpm by gear so its easy to fully maximise power vs traction.

Thanks dude, you can check the link on the first post. I don't give the car an easy time. always bouncing off the limiter. Im quite harsh on cars but its lasting so far.

Not that im aware of. I made the adaptor from 8mm steel. I made a shaft that aligned the gbox input and the k20 crank to keep it all aligned. cut the steel out and welded on dowels and studs. There are kits for the BMW gearbox to k20. Id recommend this over the s2000 gearbox option. The s2000 gearbox option is limited to around 400hp due to the single plate clutch

 

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